Blower and exhauster for moving air and gas



C. M. CONDER.

BLOWER AND EXHAUSTER FOR MOVING AIR AND GAS. APPLICATION FILED MAR. 26. 1921.

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WWWYQW till ., a horizontal at are supported atthe rear CHARLES MARKHAM CONDER, 0F CAMBORNE, ENGLAND.

BLOWER AND EXHAUSIER FOR, MOVING AIR AND GAS.

Specification of Letters Patent.

Patented Sept. 8, 1921.

Application filed March 26, 192.1. eerie]. No. 155,951.

To all whom it may concern:

Be it known that 1, CHARLES MARKHAM CONDER, a subject of the King of Great Britain, and resident of Camborne, in the county oi Cornwall, England, have invented certain new and useful Improvements in and Connected with Blowers and Exhausters for Moving Air and Gas, (for which 1 have an application in Great Britain dated January 24., 1920,) of which the following is a specification.

This invention relates to centrifugal blowers or pumps, and the object of the invention is to increase the eficiency of devicesof this kind.

in a centrifugal blower or pump the fluid which is to be moved is admitted at the center of the impeller or fan and is discharged tangentially at the periphery thereof. lhe centrifugal action depends upon the rotary movement imparted to the fluid during its passage between the blades of the impeller. ln blowers or pumps of ordinary construction this rotary movement is imparted suddenly to the fluid at the moment when it leaves the central inlet and enters the radial spaces between the blades, and such sudden change of motion is inefiicient for reasons which are well known.

In accordance with the present invention it is proposed to impart a certain degree 0 rotational movement to the entering fluid before its engagement by the blades, thus avoiding the too sudden transition from rec'- tilinear to rotary motion, and to this end the blower or pump is provided with means, either stationary, or rotary, or both, for imparting a certain degree of rotary movement to the fluid during its passage into or through the eye of the blower.

In the accompanying drawings, Figure 1 is a side-elevation of a fan-blower, shown partly in section approximately on the line 1-1 in Fig, 2; Fig. 2is a vertical section on the line 2-2 in Fig. 1, and Fig. 3 is a vertical section on the line 3-3 in Fig. 1.

The invention is illustrated as embodied in a centrifugal blower of a well known form, having a casing 5 of snail-shell form, into the eye of which air is introduced through an inlet passage or duct 6. The rotary member of the blower is carried by shaft 7, which bears, on its inner end. a head 8. The narrow blades 9 by a plate 10 fixed to the head 8, while their forward ends are Supported by a ring 11. The air or gas driven by the blower is expelled through the tangential outlet 12.

The blower, as so far described, is or may be of any ordinary or suitable form, and the novelty of the invention resides in the addition, to the members already described, of means additional to the blades 9 for imparting rotational movement to the air. One of these means is in the irons of a stationary member adapted to act uponthe air upon, or just prior to, its admission to the eye of the casing. Such stationary means may have various forms, but it is illustrated as in the form of a blade 13 with inclined ends,

fixed in the inlet-duct 6. it will be obvious that the air passing through the duct will receive a certain degree of rotary movement from the blade 13, thus causing it to traverse a helical path.

While the blade 13 facilitates the transition from the rectilinear movement of the air'to its movement in a spiral path between the blades 9 of the tan, it is desirable to assist still further this transition, and for this purpose the tan is provided with means for converting the helical motion of the air to motion in a volute path, before the air is engaged by the blades 9. To this i end the rotor is provided with several inclined blades 14:, extending from the head 8 to the ring 11, these blades being so curved and inclined that through their rotational movement they act to force the air rearwardly and outwardly while at the same time accelerating its rotational movement.

It is usual to provide tie-rods extending from the head to the ring of a blower of this type, '(see, for example, British Patent No. 10845," dated May 9 1906,) and in the illustrated blower simplicity of construction is secured b utilizing the blades 14 to perform the unction'of such tie-rods. For this purpose the blades are arranged tan entially,

and their inner ends are reduce to screw-threaded shanks 15, which are secured to lugs 16 on the head by means of nuts screwed upon the shanks.

1t willbe apparent that by the successive action of the blade 13 and the blades 14, the

motion of the air is transformed successively 'from rectilinear to helical and then to volutc,

before it finally becomes spiral in the passage of the air between the blades 9, so that the air is carried through the blower without the loss due to any sudden change in direction in the flow of the fluid.

While the invention has been illustrated as applied to a fan-blower of a certain type, it will be apparent that it is applicable to centrifugal blowers or pumps of various forms, adapted for handling both gases and I ing a rotary bladed impeller liquids, and that the invention is not, in general, limited to the details of construction illustrated and hereinbefore' described, but may be embodied in various other forms within the scope of the following claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. A centrifugal blower or pump includ having a pair of rings between which the impeller-blades extend; a shaft which carries and turns the impeller; and other blades which are fastened, at one end, to one of the rings and, at the other end, to the shaft, thereby tying the impeller thereto; said other blades lying disposed within the impeller-blades and extending thereacross, at an angle to the shaft and out of the plane thereof, and being spaced from the other ring and tapering in shape from the ring to which they are fastened at one end, toward the shaft and curved to give to the fluid a movement of a volute form in forcing the same outwardly toward the impeller-blades, whereby loss due to sudden change of direction of the fluid flow is avoided.

2. A centrifugal blower or pump including a rotary bladed impeller; a shaft which carries and turns the impeller; a casing Within which the impeller rotates; an intake duct which projects from the casing and through which the fluid is admitted thereto;

'a stationary device fixed in the duct and shaped to impart to the fluid, as the same passes through the duct into the eye of the casing, a helical rotary movement in the same direction as the movement later imparted to the fluid by the impeller-blades; and tapering blades lying disposed within the latter and spaced therefrom and from one side of the impeller, and being curved to transform the helical movement of the fluid to a volute form within the eye of the casing and in forcing the fluid outwardly toward the impeller-blades, whereby loss due to sudden change of direction of the fluid flow is avoided.

3. A centrifugal blower or pump including a rotary, bladed impeller a shaft upon which the impeller is mounted; a casing within which the impeller rotates; an intake duct which projects. from the casing and through which the fluid is admitted thereto; a stationary device fixed in the duct and shaped to impart a helical movement to the fluid as the same passes through the duct into the casing; and tapered blades which tiethe impeller to the shaft and movethere- With and which extend bodily from the shaft obliquely across the blades of the impeller to the side of the impeller opposed to the duct and are spaced from the other side of the-impeller and from the blades thereof and are shaped to impart a volute form to the helical movement of the fluid within the eye of the casing before the fluid is engaged by the blades of the impeller.

CHARLES MARKHAM CONDER. 

